High sustained +Gz acceleration produced by modern high performance aircrafts can induce brain damage because of ischemia and hypoxia. Heat shock protein 70 (HSP70) is one of the proteins broadly exist in organisms. The expression of HSP70 is an important reaction in the brain, and it has close relationship with brain ischemic injury. Now, the common view thinks that the expression of HSP70 during stimulation can protect nerve cells. This paper reviewed the biologic characteristics of HSP70 and the protective effect of HSP70 on nerve cells after brain ischemia. Also, the relationship of HSP70 expression and exposure value of +Gz were discussed.